1. Field of the Invention
The present invention relates to an image forming apparatus and more particularly to an image forming apparatus of integrated type with an image forming portion and an image reading portion.
2. Related Background Art
An image forming apparatus utilizing for example an electrophotographic method is conventionally provided with an image forming portion for charging an electrophotographic photosensitive member (photosensitive member) serving as an image bearing member, executing an exposure according to image information to form an electrostatic image on the photosensitive member, developing the electrostatic image with a developer (toner) to obtain a developer image (toner image), then transferring the toner image onto a recording material and fixing it thereby forming a recorded image. Also there is widely popular an image forming apparatus (integrated apparatus) which is not only provided with such image forming portion functioning as a printer for forming an image in response to an image information signal transmitted from an external equipment but also which is provided with an image reading portion for optically reading image information of an original to provide an electrical signal thereby functioning as a copying machine for forming an image in the image forming portion according to image information read in the image reading portion or as a scanning apparatus for transmitting the information read in the image reading portion to an external equipment such as a host computer connected communicably with the image forming apparatus.
Also in the image forming apparatus utilizing the electrophotographic method, there is employed a process cartridge system in which a photosensitive member and process means acting on such photosensitive member are integrally constructed in a cartridge and such cartridge is detachably mounted on a main body of the apparatus. Such process cartridge system allows the maintenance of the apparatus to be executed not by a service personnel but by the user himself, thereby drastically improving the operability of the apparatus. For this reason, such process cartridge system is widely employed in the image forming apparatus. It is also known to construct a developing apparatus for developing the electrostatic image forming on the photosensitive member as an independent unit (developing cartridge) detachably mountable on the main body of the apparatus.
In a small-sized or medium-sized integrated apparatus provided for example with an image reading portion above an image forming portion and with a recording material discharging portion between the image forming portion and the image reading portion, there is required a configuration allowing to open the interior of the image forming portion for handling trouble in the image forming portion or performing maintenance work such as cleaning of the interior or a replacement of consumable part (replacement part) such as the cartridge.
There is generally employed a system in which the image reading portion is made to slide in a translational movement (lateral direction) with respect to the image forming portion provided thereunder, thereby opening the interior of the image forming portion.
However, in case the image reading portion slides in a translational movement with respect to the image forming portion, it is necessary to provide rail members, bearings etc. for slidably supporting the heavy image reading portion, thereby resulting in an increase in the number of components. Also the parallel sliding of the image reading portion relative to the image forming portion increases the area occupied by the main body of the apparatus, thereby requiring a large footprint for installation.
For this reason, there is employed a system of securing a space between the image forming portion and the fixed image reading portion positioned above the image forming portion, and opening an upper cover member provided on the image forming portion thereby opening the interior of the image forming portion.
However, in order to enable access to the interior of the image forming portion by securing a space between the image forming portion and the fixed image reading portion positioned above the image forming portion, and opening the upper cover member provided on the image forming portion, it is necessary to form a sufficiently large aperture between the image forming portion and the image reading portion, whereby the height of the apparatus has to be increased, thereby resulting in drawbacks of an increased height of the copy board of the image reading portion, a deterioration in the operability and an increase in the dimension of the main body of the apparatus.